I started getting my chin hairs right after HS. The neck and sides started coming in a little later, maybe a year, with one small patch that, while slowly getting smaller, won't go away due to a scar. It's still nowhere near as thick as I'd like though. The thicker it gets, the softer I can get it.. when it first started it was like face pubes. Side note: I've noticed my pubes are getting softer over time <_<.

I was able to grow a goatee that was just my chin (it was fashionable at the time) by 19. A few years later I could grow in the mustache and have it connect, which is a big milestone. Anyway, to answer your actual question my beard was full by 25.

Oh and it’s worth mentioning that until you can grow a facial hair style fully don’t wear that facial hair style. A wispy moustache or goatee doesn’t make you look older, it makes you look awkward. Keep it clean until your face can support it.

It depends, some men doesn't grow beard until 20. You're 17 so its still early.
However, don't expect a thick beard at the first time, it will be patchy at the beginning, and you will have to keep shaving and apply beard oil to get a beard with the right thickness and consistency.

I've only got a goatee, a thin mustache, and a really terrible neckbeard and the only reason I keep the former two when I shave is to try to grow it out so i can see if I can actually grow a full beard. Took about three years from 18 to get either, so I'm slowly coming to terms that this might be it.